TestResources provides Electromechanical Compresion Test Machines mounted with biaxial flexure fixtures to precisely test your thin ceramic material. As another aid to achieve uniform loading, the loading head is articulated, being supported on a spherical seat.

The dimensions and elastic contents of the specimen, breaking load, and the radii of the support and load are used to calculate the maximum tensile stress which is at the center of the tension convex surface. Specimen warpage is also a problem when flexural testing a straight beam Reference 4requiring an articulating test fixture. For ASTM F, take a thin circular disk specimen of the ceramic and rest it on three symmetrically spaced points near its periphery.

Many turn to testing standards such as ASTM F to determine the modulus of rupture for their thin ceramic materials. The test fixture is shown in Fig. The force is applied to the ram at a constant rate in a compression test machine until the specimen breaks. It utilizes the same type of fixture, aastm specifies a specific size, namely, a 30mm support ring, a 12mm loading ring, and a 2mm cross-sectional radius of the rings.

ASTM-F – Grip-Engineering

In spite of these uniform load introduction concerns, this test method is gaining in popularity. This testing method provides a calculation of biaxial flexure strength for specimens in the as-fired condition or to test pieces prepared to have a certain thickness or surface finish. One important advantage of this biaxial test configuration is that specimen warpage is not an influencing factor, as opposed to the ring-on-ring test ASTM C A compressive loading is applied at the center of the disk specimen by a 0.

In order to attain a uniform load distribution, either the specimen surfaces must be very flat typically r394 surface grindingor a relatively thick one-half the specimen thickness sheet of a compliant material e. The standard gives expressions for calculating these parameters.

This fixture, assembled and disassembled, is shown in Figs. Sources of Additional Information: Site designed for Internet Explorer 5.

ASTM F Biaxial Flexure Fixture for Ceramic Substrates | GF

This is not the case when flexural testing a straight beam. Wyoming Test Fixtures Inc. Thus, the surface finish of the edge of the specimen is not critical. Equipment Needed TestResources provides Electromechanical Compresion Test Machines mounted with biaxial flexure fixtures to precisely test your thin ceramic material.

The minimum thickness of the specimen must be such that its center deflection at failure does not exceed one-half the specimen thickness.

Both biaxial test methods have an advantage relative to a flexural test of a straight beam in that the maximum biaxial tensile stress occurs at the center of the specimen on the lower convex when f34 side. The required diameters of the support and loading ring are dependent on the thickness and material properties of the specimen being tested. The specimen will be bent in a cupping fashion by a test machine applying force to the v394 of the disk through a cylindrical ram.